The present disclosure relates to a method and a system for detecting an ejection abnormality in a liquid ejection head having a plurality of nozzles for ejecting a liquid.
For example, an inkjet printer uses a liquid ejection head having a plurality of nozzles for ejecting an ink liquid. There may be a case where any of the nozzles becomes unable to properly eject the ink liquid due to factors such as clogging.
In detecting such an ejection failure nozzle, the liquid ejection head is operated to print a prescribed nozzle check pattern on a sheet, and the sheet is read by an optical reader. The nozzle check pattern includes check areas each drawn solely by each of the plurality of nozzles. Based on whether or not each of the check areas corresponding to the each of the plurality of nozzles is present in image data of the sheet read by the optical reader, it is determined whether or not the each of the plurality of nozzles is in an ejection failure state.